Electrical machine

Abstract

A segment for supporting electromagnetic coupling elements of a stator or rotor of an electrical machine comprises a plurality of elongate laminations which are stacked in a first direction to form a lamination stack with elongate edges of the laminations defining opposite first and second major faces of the lamination stack. The segment comprises a plurality of elongate compression devices passing internally through the lamination stack in the first direction and arranged to compress together the laminations in the lamination stack.

The invention claimed is: 
     
       1. A rotor for an electrical machine, the rotor comprising:
 a hub arranged so that the rotor can rotate with respect to a stator of the electrical machine about an axis of rotation; 
 a rim, the rim comprising a plurality of rotor rings spaced apart from each other;
 the rim further comprising a plurality of rotor ring support tube assemblies, each rotor ring support tube assembly comprising a support tube and one or more spacing elements, the spacing elements being arranged between the rotor rings so that the rotor rings are spaced apart from each other in the axial direction; 
 the plurality of rotor rings comprising a plurality of electromagnetic coupling elements for electromagnetic coupling with a stator of the electrical machine, said electromagnetic coupling elements being mounted on laminations mounted on one or more middle rotor rings; and 
 
 a plurality of spokes arranged between the hub and the rims so as to mechanically couple the hub with the rim, the plurality of spokes being arranged in pairs either side of the rotor rings in the axial direction; and
 each spoke being coupled to at least one of the rim and the hub; 
 each spoke in a pair of spokes is coupled to the rim at substantially the same position of the rim; 
 each spoke in the pair of spokes is coupled to the hub at substantially the same position on the hub; 
 the plurality of spokes are arranged tangentially with respect to a circumference of the hub; and 
 each spoke in a pair of spokes is coupled so that the spokes in the pair are offset from each other in the direction along the axis of rotation. 
 
 
     
     
       2. A rotor according to  claim 1 , in which a major axis of each spoke corresponds with a secant line passing through two points of the rim. 
     
     
       3. A rotor according to  claim 1 , comprising an adjuster for adjusting tension in one or more of the spokes. 
     
     
       4. A rotor according to  claim 1 , in which each spoke is coupled to at least one of the rim and the hub by a welded joint. 
     
     
       5. A rotor according to  claim 1 , in which hub, spokes and rim are integrally formed with each other. 
     
     
       6. A rotor according to  claim 1 , in which the electromagnetic coupling elements comprise permanent magnets. 
     
     
       7. A stator for an electrical machine, the stator comprising:
 a hub arranged so that a rotor of the electrical machine can rotate with respect to the stator about an axis of rotation; 
 a rim, the rim comprising a plurality of stator rings spaced apart from each other; the rim further comprising a plurality of stator ring support tube assemblies, each stator ring support tube assembly comprising a support tube and one or more spacing elements, the spacing elements being arranged between the stator rings so that the stator rings are spaced apart from each other in the axial direction;
 the plurality of stator rings comprising a plurality of electromagnetic coupling elements for electromagnetic coupling with a rotor of the electrical machine, said electromagnetic coupling elements being mounted on laminations mounted on one or more middle stator rings; 
 
 a plurality of spokes arranged between the hub and the rim so as to mechanically couple the hub with the rim, the plurality of spokes being arranged in pairs either side of the stator rings in the axial direction; and
 each spoke being coupled to at least one of the rim and the hub; 
 each spoke in a pair of spokes is coupled to the rim at substantially the same position of the rim; 
 each spoke in the pair of spokes is coupled to the hub at substantially the same position on the hub; 
 the plurality of spokes are arranged tangentially with respect to a circumference of the hub; and 
 each spoke in a pair of spokes is coupled so that the spokes in the pair are offset from each other in the direction along the axis of rotation. 
 
 
     
     
       8. A stator according to  claim 7 , in which a major axis of each spoke corresponds with a secant line passing through two points of the rim. 
     
     
       9. A stator according to  claim 7 , comprising an adjuster for adjusting tension in one or more of the spokes. 
     
     
       10. A stator according to  claim 7 , in which each spoke is coupled to at least one of the rim and the hub by a welded joint. 
     
     
       11. A stator according to  claim 7 , in which hub, spokes and rim are integrally formed with each other. 
     
     
       12. A stator according to  claim 7 , in which the electromagnetic coupling elements comprise permanent magnets.